Apparatus and method for dynamic resource allocation in interactive satellite multimedia system

ABSTRACT

A dynamic resource allocation apparatus and method for assigning timeslot in a return channel in multi-frequency time division multiple access MF-TDMA in order to have a maximum throughput is disclosed. The apparatus includes: resource request amount collection unit for accumulating a requested resource amount corresponding to each of terminals during a super-frame period; resource request amount processing unit for dividing an accumulated requested resource amount by the number of frame pairs in a super frame and storing a sum of a result of dividing and rounding up a remain of the division to a nearest integer as a request amount of each corresponding terminal; and resource allocation unit for deciding a time slot allocated at each of terminals corresponding to a frame pair based on optimal allocation amount, which is decided based on the request amount by the requested amount processing unit.

FIELD OF THE INVENTION

The present invention relates to an apparatus and method for resourceallocation in interactive satellite multimedia system; and, moreparticularly, to a dynamic resource allocation apparatus and method forassigning timeslot in a return channel in multi-frequency time divisionmultiple access (MF-TDMA) in order to have a maximum throughput.

DESCRIPTION OF RELATED ARTS

There have been various apparatus and methods developed for resourceallocation in a time division multiple accesses (TDMA) such as atimeslot assignment method in inter-satellite links and a resourceallocation method in TDMA in mobile communication system.

Inhere, a resource represents a frequency bandwidth used at a returnlink, which is a link between a return channel satellite terminals(RCSTs) to a satellite. That is, the resource is a set of timeslots inthe return link in multi-frequency time division multiple accessMF-TDMA. In MF-TDMA, resources are allocated as a unit of a frame or asuper-frame. One frame includes a plurality of timeslots and onesuper-frame includes a plurality of frames.

An interactive satellite multimedia system is a satellite network withone earth station (HUB) and a plurality of terminals called returnchannel satellite terminals (RCST). The earth station (HUB) receives arequest of service through satellites and provides services to terminals(RCST) through the satellite by responding to the request. In thesatellite communication system, since the radio resources are veryexpensive comparing to those in land mobile communication systems, it isone of the most important problems to maximize the link throughput usingthe limited available resources.

Specially, in the interactive satellite communication system having acentralized resource management function in the earth station (Hub), theresource needs to be allocated by considering round-trip time (RTT)spending for requesting the resource from the terminal (RCST) to theearth station (Hub) and receiving an assignment plane from the earthstation (Hub) to terminal station (RCST). In a view of allocatingresource by considering RTT, the resource allocation method in theinteractive satellite communication system is distinguished from theconventional technique for allocating resources in the satellitecommunication.

Furthermore, comparing to a timeslot assignment scheduling and packetassignment scheduling of a mobile communication system, it is alsodistinguished in view of delay of transmission and a bandwidth offrequency is comparatively broadband. In broadband TDMA, the length ofeach timeslot is usually much shorter than that in a narrow- ormedium-band TDMA. As a result, the scheduling period is getting short orthe number of timeslots per a scheduling period is getting great, bothof which make a fast timeslot scheduling more difficult, especially insuch an interactive satellite network having an intrinsic round triptime between capacity request and allocation.

As a result, it is preferred to have as short period of scheduling timeas possible in order to minimize the negative effect of the RTT.

In the interactive satellite multimedia system, therefore, it isessential that a method for reapidly and dynamically outputting aresource allocation plan to capacity request from a plurality ofterminals (RCSTs).

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide anapparatus and method for rapidly generating a dynamic resourceallocation schedule in order to maximize throughput in a return linkbased on MF-TDMA of an interactive multimedia network.

In accordance with an aspect of the present invention, there is providedan apparatus for dynamically allocating resource in an interactivesatellite multimedia system, including: resource request amountcollection unit for accumulating a requested resource amountcorresponding to each of terminals during a super-frame period; resourcerequest amount processing unit for dividing an accumulated requestedresource amount by the number of frame pairs in a super frame andstoring a sum of a result of dividing and rounding up a remain of thedivision to a nearest integer as a request amount of each correspondingterminal; and resource allocation unit for deciding a time slotallocated at each of terminals corresponding to a frame pair based onoptimal allocation amount, which is decided based on the request amountby the requested amount processing unit.

In accordance with an aspect of the present invention, there is alsoprovided a method for dynamically allocating resources in an interactivesatellite multimedia system, including the steps of: a) accumulating arequest amount of resource corresponding to each of terminals during asuper-frame period; b) dividing the accumulated request amount ofresource by the number of frame pairs included in one super frame andremembering a sum of a result of dividing and rounding off a remain ofthe division to a nearest integer as a resource request amount; and c)deciding an optimal allocation amount based on the resource requestamount and deciding a time slot to be allocated to each of terminalsbased on the optimal allocation amount.

In accordance with an aspect of the present invention, there is alsoprovided a computer readable recording medium storing instructions forexecuting a method for actively allocation resource in two-way satellitemultimedia system, including functions of: a) accumulating a requestamount of resource corresponding to each of terminals during asuper-frame period; b) dividing the accumulated request amount ofresource by the number of frame pairs included in one super frame andremembering a sum of a result of dividing and rounding off a remain ofthe division to a nearest integer as a resource request amount; and c)deciding an optimal allocation amount based on the resource requestamount and deciding a time slot to be allocated to each of terminalsbased on the optimal allocation amount.

BRIEF DESCRIPTION OF THE DRAWINGS(S)

The above and other objects and features of the present invention willbecome apparent from the following description of the preferredembodiments given in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a diagram showing a conventional interactive satellitemultimedia system;

FIG. 2 is a block diagram depicting a dynamic resource allocationapparatus in accordance with a preferred embodiment of the presentinvention;

FIG. 3 is a flowchart for explaining a dynamic resource allocationmethod in accordance with a preferred embodiment of the presentinvention;

FIG. 4 is a diagram showing a structure of a super-frame in accordancewith a preferred embodiment of the present invention; and

FIGS. 5A to 5D show results of extensive simulation of a preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Other objects and aspects of the invention will become apparent from thefollowing description of the embodiments with reference to theaccompanying drawings, which is set forth hereinafter.

FIG. 1 is a view representing a conventional interactive satellitemultimedia system.

Referring to FIG. 1, the conventional interactive satellite multimediasystem includes a plurality of terminals 11, a satellite 12 and a hoststation (HUB) 13. The terminals 11 send a request for resource to thehost station 13 through the satellite 12. The host station 13 providesservices to the terminals 13 through the satellite 12. In theinteractive satellite multimedia system, it is one of the most importantproblems to maximize a throughput according to the user's traffic.

In FIG. 1, there is only one host station and one satellite however, itis possible to include multiple host stations and satellites in thesatellite communication network.

The multiple terminals 11 simultaneously request resources to the hoststation 13 and each of terminals uses only allocated resource(timeslot).

The host station 13 receives and analyzes requests for resources fromthe multiple terminals and decides appropriate number of timeslots toassign to each of terminals according to analysis. The decision of thehost station is reported to each of terminals through the satellite 12.

The host station includes an algorithm for computing a dynamic resourceallocation schedule in order to maximize the throughput of a return linkbetween the terminal 11 to the satellite 12. The host station receivesrequests for resource of frequency from the terminals 11 and rapidlycomputes the dynamic resource allocation schedule. At this time, arequested resource for a frequency is a frequency bandwidth used for areturn link between the terminal 11 and the satellite 12. That is, therequested resource for frequency is a set of a certain number oftimeslots in the return link based on MF-TDMA. For rapidly computing aschedule for allocation resources at each of superframes, the presentinvention needs to improve the computational efficiency of timeslotscheduling by employing the so-called problem reduction anddecomposition technique, where we separately consider how to decide anamount of allocation according to each of terminals and how to selecttimeslot for allocating to each of terminals.

By using a problem decomposition method, the amount of computation canbe decreased and the speed of computation can be improved.

FIG. 2 is a diagram showing a dynamic resource allocator for dynamicallyallocating resources in accordance with a preferred embodiment of thepresent invention.

Referring to FIG. 2, the dynamic resource allocator in the host station(Hub) includes a resource request collector 21, a resource requestamount processor 22 for computing an amount of resources for allocationby dividing collected request amount to the number of frame pairs androunding off a result of division to nearest integer number, a resourceallocation amount decider 24, a resource allocation scheduler 25 and aresource allocation schedule copier 26.

That is, for scheduling the resource of the first frame pair, theresource allocation decider 24 decides the optimal amount for each framepair by considering how many frames are allocated to each of terminals11. The resource allocation scheduler 25 makes a schedule based on theoptimal amount of allocation and selects one of terminal to be assignedto allocated resource. The resource allocation schedule copier 26 copiesallocation schedule of the first frame pair to remained frame pairs inthe same superframe.

Referring to FIG. 2, the dynamic resource allocator used for the hoststation 13 includes a resource request collector 21 for accumulating anamount of request for resource during a superframe period, a resourcerequest amount processor 22 for computing a requested resource amount bydividing collected request amount to the number of frame pairs in one ofsuperframe and adding the result of dividing and rounding off a remainof division to nearest integer number and a resource allocator 23 fordeciding an optimal amount of allocation based on the request amount ofthe request amount processor 22 and deciding a timeslot to be assignedto each of terminals 11 according to the frame pairs based on theoptimal amount of allocation.

The resource allocator 23 has a resource allocation amount decider 24for deciding the optimal amount based on processed request amount in theresource request processor 22, a resource allocation scheduler 25 forselecting and deciding one of terminals RCST 11 to be allocated of atimeslot included in the first frame pair based on the optimalallocation amount and a resource allocation scheduler copier 26 forcopying timeslot allocation schedule of the first frame pair to remainedframe pairs in the same superframe.

The resource request collector 21 accumulates a requested resourceamount generated during the superframe according to each of terminalsRCST and reports it to the resource request amount processor 22. Afterreporting, the accumulated amount is set to 0 and the resource requestcollector 21 starts to accumulate the requested resource amount withnext superframe.

The resource request amount processor 22 computes an optimal amount ofallocation by dividing a resource request amount of each of terminalsRCST 11 to the number of frame pairs and rounding off a result ofdivision to the nearest integer number and the resource allocationdecider 24 decides the optimal allocation amount according to prioritiessuch as cost and weight.

The resource allocation scheduler 25 decides terminals according to eachtimeslot included in the first frame pair based on the optimizedallocation amount.

The resource allocation schedule copier 26 copies schedule of resourceallocation including a timeslot allocation schedule from the resourceallocation scheduler 25 assigned to the first frame pair to remainedframe pairs in same super-frame.

FIG. 3 is a flowchart explaining dynamic resource allocation method inaccordance with a preferred embodiment of the present invention.

At first, a unit of resource allocation according to a schedule isdefined at step of 301. That is, a super-frame and frame pair aredefined.

In MF-TDMA, the schedule for allocation is established based on a unitof frame in the superframe and one super-frame includes a plurality offrames.

A frame pair is a subset of the superframe and it is satisfied by belowconditions.

A frame pair is a set of frame having identical time period. Each offrame pairs has same arranging type of time slot and a frequencybandwidth and only difference between frame pairs is the time period.Therefore, all frame pair is a subset of the super-frame and a sum ofall frame pairs defined in a given superframe constitutes a superframe.

For example, in case of the superframe having 32 frames as shown in FIG.4, there are 16 frame pairs by pairing frame 0 and frame 16 as a oneframe pair and so on.

After defining the frame pair or superframe, the resource request amountcollector 21 remembers an ID of terminals, which are logged on at stepof 302, and accumulated request amount during one super-frame length isstored at step of 303. At the step of 303, the request amount isupdated. The accumulated request amount of each terminal is computed bydividing the accumulated request amount to the number of frame pairs inone super-frame and adding the result of division and rounding up theremain of the division to nearest integer number. A small differencewill be ignored since each request amount is reputedly allocated as manyas the number of frame pairs.

Next, the resource allocation decider 23 computes the optimal allocationamount based on request amount at step of 304 and the resourceallocation scheduler 25. The resource allocation copier 26 decidestimeslots for allocation to each terminal according to frame pair basedon the optimal allocation amount at step of 305 and 306.

At step of 305, the resource allocation scheduler 25 decides all timeslots including the first frame pair to assign to which a terminal(RCST) 11. At step of 306, a time slot allocation schedule of the firstframe pair is copied to remained frame pairs in the identicalsuper-frame by the resource allocation schedule copier 26.

For example, in case of the super-frame including 32 frames, as shown inFIG. 4, an algorithm of equations 4 and 5 is applied for deciding toallocate a time slot to a first frame pair by generating a resourceallocation schedule and for other frame pairs, the timeslots areallocated by copying the resource allocation schedule for the firstframe pair. The above mentioned method for deciding the assignment ofeach time slot can reduce calculation steps and processing time. Forexample, if there are 2000 time slots in a frame, 2000×2 times ofcalculations for the first frame are required. That is, there are 4000allocation schedules required and the other frame pairs use the computedallocation schedule for the first frame. However, if allocationschedules for all frame need to be calculated then there are 64000allocation schedules required.

Hereinafter, a step of 304 for deciding optimal allocation amountdecision of the first frame pair in the identical superframe and a stepof 305 for rapidly allocating time slot based on the optimal allocationamount are explained in detail.

At first, it is explained that the optimal allocation amount based on anaccumulated during a length of the superframe received from theterminals (RCST) 11, which is logged on.

Below equation shows original problem for dynamic allocation of timeslots.

(CAP)

${{MINIMIZE}\mspace{14mu}{g(x)}} = {\sum\limits_{j \in R}\left\lbrack {v_{i}{\sum\limits_{m \in A}{\sum\limits_{i \in S}\left( {1 - x_{ij}} \right)}}} \right\rbrack}$subject to

$\begin{matrix}{{{{\sum\limits_{m \in A}{\sum\limits_{j \in s}x_{ij}}} \leq {\min\;\left\{ {Q_{j},{X_{j} + Y_{i}}} \right\}}},{j \in R}}{{{\sum\limits_{m \in A}{\sum\limits_{j \in s}x_{ij}}} \geq {Yj}},{j \in R}}{{{\sum\limits_{j \in R}x_{ji}} \leq 1},{j \in S_{m}},{m \in A}}{x_{ji} \in \left\{ {0,1} \right\}}} & \text{Eq.~~1}\end{matrix}$

In Eq. 1, i is i^(th) time slot, j is j^(th) terminal and R is a set ofIDs of terminals logged on. A is a set of ID of return linkdemodulators, which are available. S_(n) is a set of IDs of availabletime slots and Q_(j) is the maximum number of time slots, which can beallocated to the terminal j and X_(j) is the number of time slotsrequested by terminal j, Y_(j) is the minimum number of time slots thatshould be allocated to terminal j. X_(ij) is a decision variable, whichhas a value of 1 when a time slot i is allocated to a terminal j and hasa value of 0 otherwise. V_(j) is a penalty coefficient (penalty weight).The penalty coefficient is decided according various factors such asdelay of the residual packets on the transmission queue of each terminal(RCST). That is, a large value is assigned for the penalty coefficientto the terminal (RCST) when the terminal contains a lot of delayed data.As a result, fairness of allocation resources can be achieved.

Referring to Eq. 1, g(x) is the total penalty caused by the timeslotallocation denoted by matrix [x_(ij)]. There are several conditions. Atfirst, the number of time slot for allocating to each terminal must beless than a upper bound (threshold value) or request number, which isdecided by system parameters such as construction of the super-frame.Secondly, the number of time slots for allocating to each terminal mustbe greater than lower bound, which is decided for satisfying servicequality. Lastly, each time slot cannot be allocated to two and moreterminals.

Eq. 1 can be modified to following Eq. 2 for effectively solving aproblem of resource allocation based on a concept of frame pair inaccordance with the present invention. The capacity allocation problem(CA)) can be mathematically formulated as follows:

(CAP)

${{MINIMIZE}\mspace{14mu}{g_{1}(x)}} = {\sum\limits_{j \in R}{v_{i}{\sum\limits_{m \in A}{\sum\limits_{i \in S}\left( {1 - x_{ij}} \right)}}}}$subject to

$\begin{matrix}{{{{\sum\limits_{m \in A}{\sum\limits_{j \in s_{m,1}}x_{ij}}} \leq {\min\;\left\{ {Q_{j},{X_{j} + Y_{i}}} \right\}}},{j \in R}}{{{\sum\limits_{m \in A}{\sum\limits_{j \in s_{m,1}}x_{ij}}} \geq {Yj}},{j \in R}}{{{\sum\limits_{j \in R}x_{ji}} \leq 1},{j \in S_{m}},{m \in A}}{x_{ji} \in \left\{ {0,1} \right\}}} & \text{Eq.~~2}\end{matrix}$

A difference between Eq. 1 and Eq. 2 is that the number of objects forallocation schedule is a total number of slots in a frame pair and atotal number of slots in a superframe, therefore, the processing timemay be decreased since the size of problem (CAP) and the complexityrequired to solve problem (CAP) are decreased. Furthermore, if theallocation schedule of the first frame pair is copied and used forremained frame pairs, the allocation schedule for time slots in thesuper-frame can be effectively and rapidly made.

In Eq. 2, S_(m,1) is a set of available time slots included in the firstsuperframe. The original problem (CAP) is divided to n sub-problems andoptimize x. As a result,

${g(x)} = {\sum\limits_{m = 1}^{n}{g_{n}(x)}}$at the optimal solution x.

Eq. 2 requires a preprocess of solving an allocation decision amount.

A problem of deciding an amount of allocation v_(j) is a weightrepresenting how a terminal j is important comparing to other terminal.The weight can be decided according to a service quality. For example,resources are effectively and rapidly allocated to the terminals byassigning higher priority to a terminal, which have been delayed to beallocated of resources for long period time.

${{MINIMIZE}\mspace{14mu}{f(x)}} = {\sum\limits_{j \in R}{v_{j}z_{j}}}$Subject to

$\begin{matrix}{{{Z_{j} \leq {\min\left\{ {Q_{j},{X_{j} + Y_{j}}} \right\}}},{j \in R}}{{Z_{j} \geq Y_{j}},{j \in R}}{{\sum\limits_{j \in R}^{j}z_{j}} \leq {\sum\limits_{m \in A}S_{m,1}}}{Z_{j} \in {Z\bigcup\left\{ 0 \right\}}}} & \text{Eq.~~3}\end{matrix}$

Referring to Eq. 3, Z_(j) is a decision variable denoting the number oftime slot allocated to the terminal j.

f(z) denotes a total penalty according to the amount of allocationdenoted by vector z. There are limitation conditions as followings. Atfirst, an amount of allocation of each terminal must be less a givenupper bound and request amount. Secondly, the amount of allocation ofeach terminal must be greater than a given lower bound and lastly, thetotal amount of allocation must be less than available amount ofresource.

A problem for deciding an amount of allocation is shown in below.

$\begin{matrix}{{{\text{Step~~~1~~(Sort}\mspace{14mu}\left\lbrack v_{j} \right\rbrack}\text{)}}{{k:=1},{J_{k - 1} = {\{\}}}}{\text{For}\left( {;{k<={R}};{k++}} \right)\left\{ {j_{k}:={{\arg\;\max\left\{ {v_{j},{j \in {R - J_{k - 1}}}} \right\} J_{k}}:={J_{k - 1}\bigcup\left\{ j_{k} \right\}}}} \right\}}{\text{Step~~2~~(Find~~an~~optimal}\mspace{14mu} y^{*}\text{)}}{n:={\max\;\left\{ n \middle| {{\sum\limits_{k = 1}^{n}{yjk}} \leq {{\sum\limits_{m \in A}{S_{m}}} - {\sum\limits_{j \in R}Y_{j}}}} \right\}}}{{{\text{if}\mspace{11mu} n} = {R}},{{\text{then}\mspace{14mu} y_{j}}:={{\min\left\{ {{Q_{j} - Y_{j}},X_{j}} \right\}\mspace{14mu}\text{for}\mspace{14mu} j} \in R}}}\text{Else}{y_{j}^{*}:={{\min\left\{ {{Q_{j} - Y_{j}},X_{j}} \right\}\mspace{14mu}\text{for}\mspace{14mu} j} \in J_{n}}}{{y_{m} + 1}:={{\sum\limits_{m \in A}{{Sm}}} - {\sum\limits_{j \in R}{Yj}} - {\sum\limits_{j \in J_{m}}{\min\;\left\{ {{Q_{j} - Y_{j}},X_{j}} \right\}}}}}{\text{Step~~3~~(Find~~an~~Optimal}\mspace{14mu} Z^{*}\text{)}}{Z^{*}:={y^{*} + \left\lbrack Y_{j} \right\rbrack}}} & \text{Eq.~~4}\end{matrix}$

In a Step 1, V_(j) is sorted from one having large weight to one havingsmall weight. In here, j_(k) is an ID of a terminal having k^(th)largest penalty weight (V_(j)). J_(k) is a set having {j₁, . . . ,j_(k)}.

In the Step 2, additional allocation amount is optimally decided. Atn:=max{ . . . }, the additional allocation amount is the number ofvariable timeslots Σx_(jk). If an amount of remained resource issufficient, additional requested resource is maximally allocated and ifthe amount of remained resource is not sufficient, additional requestedresource is maximally allocated to a terminal J_(n) having a highestpriority at first and then remained resource is allocated to otherterminals.

Step 3 is a step of deciding total allocation amount. The totalallocation amount is a sum of basic allocation amount and additionalallocation amount and it is computed for each terminal.

Referring to Eq. 4, a step 304 for deciding optimal resource allocationamount is explained in below.

At first, it is sorted from one having a higher weight and one having alower weight. At this time, the highest weight has an index j₁ andstored in a set J₁. Similarity, the k^(th) highest weight has an indexj_(k) and stored in a set J_(k).

After then, an additional allocation amount y*_(j) excepting minimumallocation amount is decided at step 2. At step 3, a total allocationamount z*_(j) is calculated by adding the decided additional allocationamount and the optimal allocation amount. In here, y*=[y*_(j)], andz*=[z*_(j)].

In other hand, below equation 5 shows a step 305 for deciding a timeslot to be allocated to each of terminals RCST based on the optimalallocation vector z*. That is, it is a step for choosing time slot to beallocated to each of terminals based on the decided allocation amount[z*_(j)].

$\begin{matrix}{\text{Step~~1:~~Initialization}\mspace{34mu}{{{slot\_ count}:=0},{x:=0}}\text{Step~~2 (Iteration)}\mspace{34mu}{\text{For}\mspace{14mu}\left( {{k:=1},{{k<={R}};{k++}}} \right)\left\{ \mspace{20mu}{{\text{For}\mspace{14mu}\left( {{i:={slot\_ counter}};{i < {+ j_{k}}};{i++}} \right)\left\{ \mspace{191mu}{{xi},{{{jk}:=1};}}\mspace{40mu} \right\}\mspace{40mu}{slot\_ counter}}+={z_{jk}.}}\mspace{20mu} \right\}}} & \text{Eq.~~5}\end{matrix}$

Referring to Eq. 5, a slot i is allocated to a terminal j_(k), x_(i) andj_(k) are set as 1. That is, the i is increased as many as the number ofallocation and x_(i) and j_(k) are set as 1, therefore, an amount ofallocation to the terminal j_(k) is z*_(j).

In Eq. 5, objective time slots are all of time slots in a first framepair. The time slot is allocated from one having lowest frequency(carrier) to a direction of time increase. The above mentioned step isrepeated for next carrier.

A schedule of frame pair generated in steps of 304 and 305 is copied toremained frame pairs at step of 306. Therefore, allocation schedule forall time slots included in the super-frame is completed.

As mentioned above, a reason of computing the optimal allocation amountis since values of objective equation are not changed if it is moved toany directions.

FIGS. 5A to 5D shows a simulation result of the preferred embodiment ofthe present invention for verifying an effectiveness of the presentinvention. For running simulation of the present invention, a personalcomputer with Pentium III 1.0 GHz is used. The simulation uses a modelnetwork having 128 terminals and 65024 time slots under conditions thatall weights are 1, a minimum allocation amount is 6 per a frame, amaximum allocation amount is 508 per a frame. The simulation isprogressed by randomly generating a request resource amount andmeasuring a time solving two problems of the request resource amount.

A program used for simulation has already used at a real-time resourcemanager in a host station Hub 13 and it includes a time for expressing aresource allocation schedule as a type of messaging between units of thereal system. According to the result of the simulation, it maximallytakes a time of 10 ms for deciding an allocation amount and alsomaximally takes a time of 30 ms for selecting a time slot. It also takes500 ms for requesting resource of the terminal RCST 11 to a main stationHub 13, completing an allocation schedule and the allocation schedule ispassed to the terminal RCST 11 again. Although a length of superframe isa range of 2000˜92000 ms (a standard of DVB-RCS), it is clearly showsthat a processing speed of the present invention is very fast comparingto prior art.

The above-mentioned method according to the present invention can beimplemented as instructions and stored to a computer readable recodingmedium such as a CD-ROM, RAM, floppy disk, hard disk and opticalmagnetic disk.

As mentioned above, the present invention can output resource allocationschedule in order to have a maximum throughput in a timeslot allocationin a return link based on MF-TDMA of interactive multimedia network by aproblem division method using a frame pair.

While the present invention has been described with respect to certainpreferred embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the scope of the invention as defined in the following claims.

1. An apparatus for dynamically allocating resource in an interactivesatellite multimedia system, comprising: resource request amountcollection means for accumulating a requested resource amountcorresponding to each of terminals during a super-frame period; resourcerequest amount processing means for dividing an accumulated requestedresource amount by the number of frame pairs in a super frame andstoring a sum of a result of dividing and rounding up a remain of thedivision to a nearest integer as a request amount of each correspondingterminal; and resource allocation means for deciding a time slotallocated at each of terminals corresponding to a frame pair based onoptimal allocation amount, which is decided based on the request amountby the requested amount processing means.
 2. The apparatus as recited inclaim 1, wherein the resource allocation means completes a time slotallocation schedule for a first frame pair based on an optimalallocation resource amount by deciding how to allocate resource to eachof terminals and the time slot allocation schedule is copied for otherframe pairs.
 3. The apparatus as recited in claim 1, wherein theresource allocation means includes: resource allocation amount decidingmeans for deciding an amount of resource allocated to each of terminals;resource allocation scheduling means for deciding terminals to beallocated of variable time slot included in a first frame pair based onthe amount of resource decided by the resource allocation amountdeciding means; and resource allocation schedule copying means forcopying an allocation schedule of time slot in the first frame pair forremained frame pairs in same super-frame.
 4. The apparatus as recited inclaim 3, wherein the frame pair is a subset of the super-frame, one offrame pairs is a set of frames or a frame having identical time period,each of frame pairs have identical a time slot allocation type or afrequency bandwidth and different time period comparing to other framepairs, all frame pairs in one super-frame are subsets and a union of allframe pairs is the super-frame.
 5. The apparatus as recited in claim 4,wherein the resource request amount processing means obtains a resultcomputed by dividing the request resource amount of each terminal by thenumber of frame pairs in one super-frame and rounding off a result ofdivision to the nearest integer.
 6. A method for dynamically allocatingresources in an interactive satellite multimedia system, comprising thesteps of: a) accumulating a request amount of resource corresponding toeach of terminals during a super-frame period; b) dividing theaccumulated request amount of resource by frame pairs included in onesuper frame and remembering a sum of a result of dividing and roundingoff a remain of the division to a nearest integer as a resource requestamount; and c) deciding an optimal allocation amount based on theresource request amount and deciding a time slot to be allocated to eachof terminals based on the optimal allocation amount.
 7. The method asrecited in claim 6, wherein in the step c), a time slot allocationschedule of a first frame pair is decided based on the optimalallocation amount by deciding the optimal allocation amount based on theresource request amount in the step b) and the time slot allocationschedule of the first frame pair is copied and used for other framepairs.
 8. The method as recited in claim 6, wherein the step c) includesthe steps of: d) deciding how much resource is allocated to each ofterminals based on the first frame pair; e) deciding terminals to beallocated of a variable time slot included in the first frame pair baseon the optimal allocation amount; and f) copying a time slot allocationschedule of the first time slot to remained frame pair in the same superframe.
 9. The method as recited in the claim 8, wherein in the step d),the optimal allocation amount is decided according to a priority ofresource request amount processed at the step b), an additionalallocation amount excepting minimum allocation amount is decided bysorting the resource request amounts from one having higher weight toone having lower weight and a total allocation amount is calculated byadding the additional allocation amount and the optimal allocationamount.
 10. The method as recited in the claim 6, wherein in the stepb), a result is obtained by dividing the request resource amount of eachterminal by the number of frame pairs in one super-frame and roundingoff a result of division to the nearest integer.
 11. A computer readablerecording medium storing instructions for executing a method foractively allocation resource in two-way satellite multimedia system,comprising functions of: a) accumulating a request amount of resourcecorresponding to each of terminals during a super-frame period; b)dividing the accumulated request amount of resource by frame pairsincluded in one super frame and remembering a sum of a result ofdividing and rounding off a remain of the division to a nearest integeras a resource request amount; and c) deciding an optimal allocationamount based on the resource request amount and deciding a time slot tobe allocated to each of terminals based on the optimal allocationamount.